welcome to health care magic.
well you need two mammaogrphs if there is any doubt in your mammograph. it may be due to an artifact or just a transient leison. so a repeat one is needed. do not worry. this is for your safety. if there is any doubtful/suspicioud pathology then a different view in the mammography
may be needed like a magnification of a particular area. also an ultrasonography
of the breast should be combined with it.